Such a preparing device is known from the prior art. This known preparing device is often used in practice for preparing hot beverages, such as coffee or tea.
Devices of this type prepare a hot beverage from hot water and powder. This powder is supplied to a mixing chamber from a reservoir. Hot water is then added to the mixing chamber in order to dissolve the powder in the former by mixing. The hot water is accompanied by vapour. If this vapour reaches the powder inlet, lumps will form in the latter and lead to clogging. In addition, the powder supplied also causes some fine powder particles to fly up and spread together with the vapour. The latter makes it necessary to extract the vapour and the swirling powder particles. Said extraction is effected by means of an extraction duct.
However, it is a drawback of the known device that the extraction duct is difficult to (un)install. In the known preparing devices, the extraction duct extends through the housing of the preparing device. In this case, the extraction duct winds itself through the spaces between the components accommodated in the housing, including electrical components and pipework. As a result, removal and fitting of the extraction duct involves complicated operations, such as disassembling the first housing. These operations are cumbersome and take up a relatively large amount of time. One of the results is that, in practice, the extraction duct is not cleaned or replaced sufficiently often. During use, the extraction duct tends to become soiled quickly, as the combination of air, moisture and powdery particles travelling through the extraction duct has the tendency to stick against the inner wall of the latter. This subsequently forms an encrusted substance on the inside walls of the extraction duct. As a result, the extraction duct initially becomes partially blocked and subsequently completely blocked. This has an adverse effect on the operation of the preparing device and on the flavour of the beverages prepared with the latter. If the extraction is poor, the preparing device will soil quickly. This has to be prevented due to food safety and hygiene standards for the preparing device. Furthermore, a partially or completely blocked extraction duct increases the risk of causing the extraction duct to leak, which may in turn lead to failures and malfunctions of the components accommodated in the housing, such as electrical components.
As the extraction duct extends through the housing, there is a great risk of failures and malfunctions of the components which are inside the housing when the extraction duct starts to leak. Another drawback is the fact that the housing has openings leading to the interior thereof. These openings increase the risk of pollution and moisture entering the housing, which will result in failures and malfunctions of the components housed in the housing.
A preparing device is disclosed in EP 1,088,505. In FIGS. 3, 4 and 5, this publication illustrates, in a highly diagrammatical form, a mixing chamber (9) provided with a mixing member (14) which is driven around a vertical shaft (13) by means of a mixing motor (10) placed vertically above the mixing chamber (9). Five of these mixing chambers are connected to an extraction duct 15 via connecting apertures (16A-E). This extraction duct (15) consists of a top section (16) and a bottom section 20. On the underside of the bottom section (20), a ventilating fan (23) is provided. In order to detach the top section (16) from the bottom section (20), vertical screws 24 have to be removed, which are accessible from below. This publication does not describe how this assembly is accommodated in the preparing device. However, as the mixing motors (10) have to be screened off by the housing when replacing the reservoirs (1A-G) for powder, and are in a slightly higher position than the upper side of the extraction duct (15), and because the reservoirs in FIG. 1 are at a relatively large distance above the mixing motors, it is clear that the mixing motors and the extraction duct will jointly be screened off with respect to the reservoirs, probably by means of a closed housing. The extraction duct in accordance with EP 1,088,505 can thus not be removed in a simple manner, something which is confirmed by the fact that the screws (24) are difficult to access from below.